Navegando por Assunto "Radiopropagation"

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Acesso aberto (Open Access)
Redes neurais aplicadas à modelagem de canais de comunicação utilizando VANTs e dispositivos IoT
(Universidade Federal do Pará, 2023-02-08) CARDOSO, Caio Mateus Machado; BARROS, Fabrício José Brito; http://lattes.cnpq.br/9758585938727609; ARAÚJO, Jasmine Priscyla Leite de; http://lattes.cnpq.br/4001747699670004
After the occurrence of the cellular networks fifth generation auction (5G), carried out by the National Telecommunications Agency (ANATEL), carriers started to implement the technology on Brazilian soil and it is expected that a massive amount of smart devices will become capable to connect to 5G networks, promoting the advancement and improvement of internet of things (IoT). However, Narrowband-IoT (NB-IoT) technology, used by 5G for IoT applications, is still not enough to meet all user requirements, with that in mind, LoRa technology emerges as an auxiliary to meet the requirements of users. Given this scenario, this work aims to analyze the behavior of the LoRa signal in a suburban and densely wooded environment. For this, measurement campaigns are carried out at the Federal University of Pará (UFPA) and from the collected data a neural network model capable of reproducing this behavior is proposed. The standard model is compared to baseline models and proves to be superior in the downlink and uplink scenarios with a minimum RMSE error of 1,6623 dB for the first and 1,3891 dB for the second
Acesso aberto (Open Access)
SIMPLARCOM: simulador para planejamento de redes de comunicação sem fio utilizando realidade virtual e modelos de propagação
(Universidade Federal do Pará, 2014-04-25) PINHEIRO, Diego Carneiro; RIBEIRO FILHO, Manoel; http://lattes.cnpq.br/9329438229733907
This simulator is formed by the junction of Virtual Reality techniques with propagation models, developed through the studies of radio enlace, describing the loss that the transmitted signal suffers along the way in the environment. The Simulator has two modules. The first allows the creation of virtual environment with the placement, on a ground, buildings, trees, cars, antennas and other primitives that allow the construction of a customizable three-dimensional environment. The second module allows the configuration of the parameters related to antenna signal propagation as power, frequency, gain, etc., and also selects the propagation model for the simulation execution. Within this second module, there is a submodule responsible for coverage area planning study composed by antennas, in other words, this submodule simulates the distance that each antenna in the scenario can reach and generates its coverage area. To demonstrate the Simulator efficiency was created two virtual environments for testing. A scenario representing an urban environment where employed a classic propagation model, Okumura-Hata to small and medium-sized cities, and a wooded three-dimensional environment using a specific model for propagation simulation of densely wooded regions, developed at the Federal University of Pará called Lyra- Castro-UFPA.